orthochromatic
/ˌɔːθəʊkrəˈmatɪk
/adjective
(Of black-and-white photographic film) sensitive to all visible light except red. Orthochromatic film can therefore be handled in red light in the darkroom but does not produce black-and-white tones that correspond very closely to the colours seen by the eye. Often contrasted with panchromatic.Even the orthochromatic films were not sensitive to red light....
- I use traditional panchromatic films for the interpositive and an orthochromatic film for the final enlarged negative.
- As plates and films became more sensitive (orthochromatic emulsions are sensitive to green as well as blue light), ruby safelight filters became necessary, but the old manipulation techniques could still be utilized.